Record Section of Regional Waveforms from Explosion on 08/31/97

This record section (seismograms plotted with distance and time) shows
vertical-component regional waveforms from the Depth of Burial
Experiment in Kazakstan. Records are from 25-ton shot at 300 m depth
on August 31, 1997 and are recorded by L4C (T0=1 s) short-period
sensors at sites in Kazskstan. The explosion is conducted at a unused
borehole in Balapan (former Soviet Nuclear Test Site). Waveform data
at near-field (few km to about 20 km) have been acquired by field
instruments deployed by LANL/NNC team. While regional waveforms at
distance ranges of 100 - 1000 km have been acquired by LDEO/NNC
deployment supported by the Lawrence Livemore National Laboratory (LLNL).
Note that the seismograms are plotted with group velocity axis
(epicentral distance in km / time after the origin time in sec),
this kind of plot is not common, but it gives clear picture of apparent
speeds of the various characteristic regional waves such as, Pn, Pg,
Sn and Lg.